Equipotent subanesthetic concentrations of sevoflurane and xenon preventing cold-stimulated vocalization of neonatal rats.

摘要: BACKGROUND The effects of inhaled anesthetics on the developing brain are studied using neonatal rodents exposed to fractions minimum alveolar concentration (to avoid cardiorespiratory compromise). However, these cannot be assumed equipotent. Xenon's anesthetic and neuroprotective properties warrant investigation in models. Therefore, equipotent, subanesthetic concentrations needed. METHODS Forty-eight Wistar rats (Charles River Laboratories, Kent, United Kingdom) postnatal day 9 were randomized eight anesthetics: isoflurane, sevoflurane, or xenon. Exposure was closely monitored individual metal-based chambers resting a 35°C mat maintain normothermia. A 25°C used stimulate vocalization sound recording made (1 min, 1 100 kHz). Rectal temperature partial pressure carbon dioxide pH mixed arteriovenous blood measured immediately after exposure. Concentration-response models constructed logistic regression (dependent variable: explanatory concentration). all other variables assessed by inserting them individually into model. RESULTS effective preventing cold-stimulated 50 95% (EiC50 EiC95) 0.46 0.89% sevoflurane 20.15 34.81% xenon, respectively. effect EiC50 variables, including duration, minimal. Stability isoflurane not achieved over three durations (40, 80, 120 min exposure). Partial appeared normal. CONCLUSIONS authors report equipotent xenon with preserved cardiopulmonary function. This may useful designing rodent anesthesia.